Control units are usually made up of a circuit board, on which electronic components are placed, and a housing. In engine control units, a male multipoint connector is usually mounted on the circuit board in order to establish the electrical connection between a wire harness plug and the circuit board. The male multipoint connector thus represents an additional component in the assembly of the control unit. So-called electrical direct contacts are also known in which the male multipoint connector is omitted and the individual poles of the wire harness plug are contacted directly on the circuit board. For this purpose, electrical contact surfaces (“lands”) are provided on the circuit board, which are contacted by contact elements, which are plugged into the wire harness plug.
Direct plug connections may require contact pressure reinforcement for the plug connection when contacting the contacts on the circuit board unilaterally. This contact pressure reinforcement acts against the sum of the normal contact forces exerted by electrical contact elements of the plug on the contact surfaces. Currently implemented design approaches provide spring elements for this purpose, which are component parts of the wire harness plug. It is believed that this may entail the following disadvantages, however:                The functional component “contact pressure reinforcement for the wire harness plug” has an unfavorable effect on a reduction of the size of the wire harness plug.        Existing design approaches display an application of force on the structure of the wire harness plug that is not easy to optimize in practice. Since wire harness plugs are normally made of plastic and are therefore subject to a permanent flow behavior as a function of temperature and stress, this aspect cannot be ignored.        Existing design approaches have spring elements that already require a pretensioned contact pressure spring even in the case of a wire harness plug that has not been contacted. This has an unfavorable effect on the dimensioning of the spring.        Existing design approaches have layouts that require spring expansions that run counter to the expansions necessary in the event of a load (i.e. when the wire harness plug is plugged). This has an unfavorable effect on the dimensioning of the contact pressure spring and the plug-in force.        Existing design approaches have layouts, which, when applying the contact pressure force via the contact pressure spring, produce opposing forces or moments that counteract the actual contact pressure force.        